This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This project is designed to investigate (a) the development of hippocampal and peripheral cortex functions in monkeys, (b) the long-term consequences of early insult to these brain areas on the maturation of memory processes and social bonds, and (c) the anatomical reorganization of other brain systems resulting from these early lesions as compared to adult lesions. In the current year, we continued to behaviorally trained monkeys that we have prepared with neonatal lesions of the hippocampus and their sham-operated controls as they are reaching adolescence and early adulthood. We have assessed their abilities to recognize objects and places over long delays, to hold information on line while performing a task, as well as their social skills and emotional reactivity. We began to behaviorally train another cohort of 6 infant monkeys with neonatal lesions of the peripheral cortex as well as 2 sham-operated and 2 normal infants that will serve as controls. These animals are being tested on object recognition memory, social interactions and emotional reactivity during their second year. We will pursue the behavioral testing of these animals as they will mature. Through this research we anticipate that principles of the brain's response to damage can be established that will lead ultimately to the discovery of ways in which such effects can be alleviated or even eliminated.